Water intolerance
In "Signs," the alien invaders are revealed to be vulnerable to water. This vulnerability allows the characters to successfully defend themselves by using water as a weapon, leading to the defeat of the aliens. The film ends with the surviving characters rebuilding their lives in the aftermath of the invasion.
There is no evidence that aliens exist therefore the biology of aliens, if they do, is unknown
Their primary weakness at this point is that they don't appear to actually exist! If aliens ever do show up in real life, their weaknesses will depend on their biology and technology, which cannot be predicted in advance. Nobody no's I am affraid because nobody can be positive that aliens exist so (That I know of) Nobody can answer your question correctly HOWEVER if I use my imagination ... I would guess that its weakness is guns OR homosapians (Humans :] ) We may scare them so much. ALTHOUGH it is only a guess ... Sorry can't answer this question correctly :(
They are called Scardox Aliens.
If there are aliens
There are no aliens.
yes. we think other species are aliens because we dont know what they are. maybe aliens dont know about us and think we are aliens.
Aliens can be deported. You can not deport a citizen. Aliens cant vote Aliens can not run for political office
If we were there, we would be aliens. If they were here, they would be the aliens. Depends on the type of alien.
There are no such thing as aliens
Yes, there are aliens in California at a little market it has a U.F.O with aliens shopping for laser beams [the aliens and the U.F.O are models].